JOURNAL OF CHEMICAL THERMODYNAMICS
·
2022
·
IF 3.269
Jinkun Guo,Bo Jin,Shijin Chu,Rufang Peng
A different type of heat-flow calorimeter is developed to measure the energy of combustion. This calorimeter uses differential thermopile as the heat-flow sensor. The calorimeter and oxygen bomb have a special structure to ensure that the heat generated by combustion heat is slowly transferred to the thermopile, and the temperature of the outside interface of the thermopile is constant. The calorific coefficient is determined by chemical calibration, providing for the chemical calibration S =(64.806 ± 0.029) μV mW −1 , which means uncertainty is 0.05 % for calibration. The combustion enthalpies of anthracene and naphthalene are measured by using this calorimeter, and the results agree with the literature values or recommended values.
研究领域:
热化学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2020
·Vol. 10
·期 10
·2013
·
IF 4.324
Jun Dong,Weili Wang,Xiaofeng Wang,Shaojun Qiu,Maohua Du,Bo Tan,Yanjing Yang,Taizhong Huang
To improve the engine-driven performance of propellants, high-energy alloys such as Al and Mg are usually adopted as annexing agents. However, there is still room for improvement in the potential full utilization of alloy energy. In this study, we investigated how to improve combustion efficiency by decorating Al3Mg2alloy with multilayer graphene and amorphous boron. Scanning electron microscopy and Raman tests showed that decorating with multilayer graphene and amorphous boron promoted the dispersion of Al3Mg2alloy. The results showed that decorating with 1% boron and 2% multilayer graphene improved the combustion heat of Al3Mg2alloy to 32.8 and 30.5 MJ/kg, respectively. The coexistence of two phases improved the combustion efficiency of the matrix Al3Mg2alloy.
研究领域:
材料科学
·
燃烧化学
✓ 已验证
DOI
高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2021
·Vol. 46
·期 8
·1240-1247
·
IF 1.887
Hongyi Zhang,Xinyi Du,Gang Li
Boron is a well-known high-energy solid. A thick oxide coating on the particle, however, inhibits its ignition and reduces its energy significantly. In this work, graphene nanosheets were used as a protective material for encapsulating boron nanoparticles (NPs) to prevent their oxidation from the air at room temperature. Boron-reduced graphene oxide (RGO) composites were prepared under hydrothermal conditions using graphene oxide (GO) and commercial or washed boron NPs as precursors. Boron-RGO composites were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetry (TG), and differential scanning calorimetry (DSC). XPS data show that no boron oxide or boric acid was present on the surface of washed boron particles and boron-RGO composites. It seems that the removal of boron oxide or boric acid layer on the commercial boron particle surface and the reduction of graphene oxide occurred simultaneously during hydrothermal treatment. XRD data show that boric acid re-formed on washed boron NPs but not on the boron-RGO composites after these two samples had been exposed to ambient temperature air for four months. This indicates that the anti-oxidation stability of boron against air at room temperature was improved greatly after encapsulation of reduced graphene oxide. The heat of combustion of boron-RGO composites (46.6∼49.3 kJ ⋅ g −1 ) measured by oxygen bomb calorimetry was higher than that of the commercial boron NPs (43.4 kJ ⋅ g −1 ). Upon heating, the boron-RGO composite begins oxidizing at a lower temperature than the commercial boron particles. A mechanism was proposed for encapsulation of boron NPs with RGO.
研究领域:
材料科学
·
能源材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2017
·
IF 3.648
Tian Tian,Xiaoling Hu,Ping Guan,Shuangjie Wang,Xiaoqi Ding
Energetic ionic liquids (EILs) based upon nitrate, perchlorate and dicyandiamide salts of 1-alky/esteryl-4-amino-1,2,4-triazolium are synthesized. The structures are characterized by 1 H NMR, FT-IR and element analysis. The density, constant volume combustion heat and specific heat capacity of these EILs are determined through experiment. Their interaction energies of ion pairs , standard molar volume , standard molar heat capacity and standard molar enthalpy of formation are calculated by DFT/B3LYP/6-311 + G(d,p) and further researched. The thermodynamics function data relative to the reference temperature (298 K) are obtained based on the C p from 303 to 353 K. The influences of temperature, molecular structure and interaction energy of ion pairs on ρ and C p are also discussed systematically. In addition, the density and thermodynamic properties of EILs are deduced from theoretical calculation and experimental evidences. As a result, the physicochemical properties estimation of EILs using theoretical calculation method can be applied in the field of modern military, science, etc.
研究领域:
化学
·
材料科学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2021
·
IF 3.383
Slimane Abdous,Mehdi Derradji,Oussama Mehelli,Raouf Belgacemi,Azzedine Khadraoui,Yacine Laichi,Hamza Djerra,Noureddine Ramdani,Wenbin Liu
In this study, three new energetic benzoxazine monomers were synthesized via a one-step Mannich reaction process involving the incorporation of explosophore nitro groups (NO 2 ) in different positions (ortho, meta and para) into the monomer backbone. The molecular structures of the synthesized monomers were confirmed by FTIR, 1 H and 13 CNMR techniques. The curing behavior, thermomechanical properties and the thermal stability were assessed by DSC-TGA analyses. All monomers displayed two exothermic peaks related to the polymerization and degradation steps except 4-NBZ that present the polymerization and the degradation phenomena through one unique exotherm pic. The energetic performances were evaluated by the determination of the heat of combustion using a bomb calorimeter in an oxygen atmosphere. The results indicated that the para position provided the benzoxazine monomers with a high calorific value comparable to that of the nitrocellulose (about 10.401 kJ/g). Meanwhile, the aforementioned monomer was found to ignite at a temperature of about 267 °C. Overall, this study showed that the ease of synthesis of the benzoxazine resins via Mannich reaction can be further extended the energetic field and further researches are undergoing to fully unravel the potential of these exceptional materials.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
Crystals
·
2022
·Vol. 12
·期 7
·948
·
IF 2.67
Haolong Zhai,Xiaoping Cui,Yuping Gan
Taking the combustion tear gas mixture as the research object, the system formula was optimized by adding a different mass fraction of 5-amino-1H-tetrazole(5AT). TG-DSC, a thermocouple, and a laser smoke test system were used to characterize the characteristic combustion parameters such as combustion temperature and velocity, as well as the end-point effects such as smoke concentration and particle size. Starink’s method, the Flynn–Wall–Ozawa method, and the Coats–Redfern method were used to evaluate the pyrolysis kinetic parameters of the samples. The results show that when the mass fraction of 5-amino-1H-tetrazole in the system is 10%, the maximum combustion temperature of the sample decreases by nearly 70 °C and the smoke concentration increases by 12.81%. The kinetic study also found that with a different mass fraction of 5-amino-1H-tetrazole in the system, the main reaction model of the mixed agent in the first, third, and fourth stages of pyrolysis changed significantly, but for the second stage of sample pyrolysis, the main reaction model (the A4 model) showed a high degree of consistency, which can be considered as the thermal diffusion stage of the tear agent capsicum oleoresin (OC) (the temperature range is 220~350 °C), which is highly consistent with the results of the TG-DSC analysis. It was also confirmed that OC’s thermal diffusion is mainly concentrated in this stage. The results of this study show that adding an appropriate amount of the combustible agent 5-amino-1H-tetrazole to the combustion tear gas mixture can improve its combustion performance and smoking performance, which provides an important, new idea for the development of a new generation of safe, efficient, and environmentally friendly tear gas mixtures.Keywords:5-amino-1H-tetrazole;tear gas mixture;combustible agent;combustion pyrolysis characteristics;dynamics research
研究领域:
化学
·
材料科学
·
热分析
✓ 已验证
产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2022
·
IF 4.966
Xiaoling Fan,Fei Xin,Wenchao Zhang,Haoyu Liu
A novel phosphorus-containing flame retardant PZN@UiO-66-NH 2 was synthesized by covalent bonding between HCCP and UiO-66-NH 2 , and applied in unsaturated polyester (UPR). The Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron energy spectra (XPS), scanning electron microscopy (SEM) was used to confirm the chemical structure of PZN@UiO-66-NH 2 . The appearance of new P-N-C bond indicated that HCCP was successfully reacted with UiO-66-NH 2 . The thermal stability and the flame-retardant properties of the UPR composites were characterized by thermogravimetric analysis (TGA), limiting oxygen index (LOI) and cone calorimeter test. The limiting oxygen index (LOI) of UPR composite with 4 wt% PZN@UiO-66-NH 2 can reach 23.9%. Compared with pure UPR, the peak heat release rate (PHRR) value, total heat release (THR) value and average effective heat of combustion (av-EHC) value of UPR composite with 4 wt% PZN@UiO-66-NH 2 dropped by 36.53%, 28.70%, 23.50%, respectively. The addition of PZN@UiO-66-NH 2 slightly improved the impact performance of UPR composite. PZN@UiO-66-NH 2 can solve UiO-66-NH 2 's agglomeration dilemma in UPR to some extent.
研究领域:
材料科学
·
高分子科学
·
阻燃性能
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Yumei Shu,Xiaoyu Wang,Tinghao Jia,Lun Pan,Qingfa Wang,Xiangwen Zhang,Ji-Jun Zou
Biomass-based aviation fuel is attractive for sustainable development. Herein, we report a facile route to synthesize alkyl-adamantanes (AAMs) via acid-catalyzed rearrangement of biomass polycyclic sesquiterpene derivatives (bio-PCS derivatives). The reaction conditions including catalysts, solvents, reaction temperature and reaction time were optimized. Notably, a total AAMs yield of 65.1% was achieved under the optimal conditions. The kinetics of rearrangement reaction was investigated, and the reaction rate constant ( k ) and apparent activation energy ( E a ) were calculated based on the experimental kinetic data. The rearrangement products possess high density of 0.90 g/cm 3 , high net heat of combustion of 42.6 MJ/kg, low viscosity (22.5 mm 2 /s at −20℃) and high thermal oxidative stability. The blending of rearrangement products with JP-10 can significantly shorten the ignition delay time (IDT) of JP-10. This work provides a method to synthesize high-performance biomass-based AAMs.
研究领域:
化学工程
·
可持续能源
·
催化
·
航空燃料
✓ 已验证
产品关联
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2018
·
IF 1.047
Shuang Yang,Yefa Hu,Qiaoxin Zhang
In this article, a phosphorus–nitrogen-containing flame retardant (DOPO-T) was successfully synthesized by nucleophilic substitution reaction between 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and cyanuric chloride. The chemical structure of DOPO-T was characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance (NMR) and phosphorous-31 NMR, and elemental analysis. DOPO-T was then blended with diglycidyl ether of bisphenol-A to prepare flame-retardant epoxy resins. Thermal properties, flame retardancy, and combustion behavior of the cured epoxy resins were evaluated by differential scanning calorimetry, thermogravimetric analysis, limited oxygen index (LOI) measurement, UL94 vertical burning test, and cone calorimeter test. The results indicated that the glass transition temperature (Tg) and temperature at 5% weight loss of epoxy resin (EP)/DOPO-T thermosets were gradually decreased with the increasing content of DOPO-T. DOPO-T catalyzed the decomposition of EP matrix in advance. The flame-retardant performance of EP thermosets was significantly enhanced with the addition of DOPO-T. EP/DOPO-T-0.9 sample had an LOI value of 36.2% and achieved UL94 V-1 rating. In addition, the average of heat release rate, peak of heat release rate, average of effective heat of combustion, and total heat release (THR) of EP/DOPO-T-0.9 sample were decreased by 32%, 48%, 23%, and 31%, respectively, compared with the neat EP sample. Impressively, EP/DOPO-T thermosets acquired excellent flame retardancy under low loading of flame retardant.
研究领域:
材料科学
·
高分子化学
·
消防安全工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）